So the case is that dielectric engineered fluid is non-flammable. There is an NFPA 704 standard called "Standard System for the Identification of the Hazards of Materials for Emergency Response", maintained by the U.S.-based National Fire Protection Association. NFPA 704 classifies Thermasafe R flammability as 1 on a scale of 0 to 4, which means "Materials that require considerable preheating, under all ambient temperature conditions, before ignition and combustion can occur (e.g. mineral oil, ammonia). Includes some finely divided suspended solids that do not require heating before ignition can occur. Flashpoint at or above 93.3 °C (200 °F)." However, in operational conditions, our fluid will be classified as 0. It means "Materials that will not burn under typical fire conditions (e.g. Carbon tetrachloride), including intrinsically noncombustible materials such as concrete, stone, and sand. Materials that will not burn in air when exposed to a temperature of 820 °C (1,500 °F) for a period of 5 minutes." Now - the Thermasafe R dielectric immersion fluid flashpoint is 160C/320F. And it cand get fire only if the whole fluid amount reaches this temperature. So you would have to put huge amount of energy to get the whole enclosure (200-230L) to that temperature. In server immersion, where the enclosures hold 600-800L of fluid, it's virtually impossible to heat this fluid amount to this point. Both servers and ASIC miners have thermal protection build int and some components may reach up to 80C or more, but this is the end - at that point devices will start to shut down, so we have still 80C to cover to reach 160C and to be able to ignite the fluid. But wait - if someone will use some heaters and artificially push lots of kW of energy to push the temperature up to 160C? Well, not possible. The fluid in the enclosure constantly circulates. In the five minutes, we pump almost 500L of fluid through the fittings with delta T of 20C. It means the heat is constantly transported to the outside heat rejection device - some dry cooler or pool, or tap water, or any closed loop at home. So summing up - during the operation of the system exposing our enclosure full of pumped fluid to a temperature of 820C for 5 minutes - it will be the last thing that can ignite. You virtually can't get better than that. IMMERSION COOLING HAS FIRE PROTECTION BUILD INTO THE SYSTEM.
